Sample Size Calculator
n = (Z² × p(1−p)) ÷ e² (adjusted for finite population)Z=1.96, p=0.5, n≈370 (with finite pop correction)
Free online tool
Sample Size Calculator
Enter population size, confidence level and margin of error.
Instant calculation
Sample Size Calculator
Enter population size, confidence level and margin of error.
Your result
Calculation
Your numbers stay in this browser. Nothing is uploaded or saved.
Three clear steps
How to use this calculator
- 01
Enter population size
Type the total population being studied.
- 02
Set confidence level
Enter the desired confidence level (e.g., 95).
- 03
Set margin of error
Enter the acceptable margin of error (e.g., 5%).
The formula
How this calculation works
Uses the standard sample size formula with finite population correction. Z=1.96 for 95% confidence.
Check the method
Worked examples
Each example follows the same formula used by the calculator.
Population 10,000, 95% confidence, 5% margin — sample size?
Z=1.96, p=0.5, n≈370 (with finite pop correction)≈ 370 respondents neededCommon questions
Questions about this calculation
What is the Sample Size Calculator?
The Sample Size Calculator helps you calculate the minimum sample size needed for a survey or study. Enter your values and select Calculate to get an instant result.
How is the result calculated?
Uses the standard sample size formula with finite population correction. Z=1.96 for 95% confidence.
Can you show an example?
Example: Population 10,000, 95% confidence, 5% margin — sample size? — ≈ 370 respondents needed.
Is my data saved when I use the Sample Size Calculator?
No. All calculations run locally in your browser. Your inputs and results are never uploaded, stored or shared with anyone.
Is the Sample Size Calculator free to use?
Yes. The Sample Size Calculator is completely free. No account, sign-up or payment is required. It works on mobile, tablet and desktop.
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